Corn (monocot) and soybeans (dicot), for example, can be rotated in various crop rotation cycles in various geographies. Cotton is also a dicot.
“Volunteer” plants are unwanted plants from the prior growing season that emerge in a field planted with crops for the current growing season. Volunteers are basically weeds, and can, like weeds, reduce harvest and yield of the crop of interest for the current growing season. The volunteers divert fertilizer resources and the like from the desired crops.
Unlike plain weeds, volunteers are often specifically engineered to be resistant to some herbicides. Thus, controlling volunteers can be more difficult than controlling naturally occurring weeds.
AAD (aryloxy alkanoate dioxygenase) genes as described herein impart high levels of tolerance to 2,4-D herbicides in plants that are transformed with an AAD gene.
AAD-1 genes (encoding SEQ ID NO:1, SEQ ID NO:2, and SEQ ID NO:3, for example, of the attached sequence listing; see WO 2005 107437) also impart high levels of tolerance to phenoxy- and aryloxyphenoxyproplonate herbicides (“fops” such as fluazifop and haloxyfop) to corn and other monocot species transformed with the gene. (Fops are primarily used to control monocots, as dicots tend to have some natural resistance to fops.) Thus, AAD-1 allows the use of some fops as either selection agents or as herbicides on crops where crop destruction would be expected without the AAD-1 gene.
AAD-12 and AAD-13 genes also impart high levels of tolerance to pyridyloxyacetate herbicides (such as triclopyr and fluroxypyr; “pyrs”). Thus, AAD-12 and AAD-13 each allow the use of pyrs as either selection agents or as herbicides on crops where crop destruction would be expected without the AAD-12 or AAD-13 gene.
There are very numerous types of monocot- or grass-only herbicides (that kill monocots).
ACCase inhibitor herbicides include fops and dims.